When the Barclays Silver ETC (SLV) was approved in 2006 (after about a year), there was a period of about a month after they cleared the last regulatory hurdle from the SEC, and when it got final approval. Likewise, there was a potential a period of about a week from when they got final approval and when it could begin trading, although iirc it was only a day or two.
So, there could conceivably be some notice.
I agree though that I think the SEC is going to drag its heels and be slow to approve this if they ever do. Silver did go from around $10/oz in April 2006 to around $50 to around $20, some of which may have been due to the ETF.
It is good that there is money behind this because it could be a long, expensive process.
I plan to keep accumulating bitcoin until the IPO. I'd REALLY love to see an alternative currency ETF, too, something that invested in a basket of the top 20 largest cryptos... That would really do well. If only I had the money to start one!